Wavepad Audio Editor for Mac is a tool that allows you to change and alter your audio tracks, and it allows you to add effects and trim your tracks. The sad part about this tool is that it is free to download and install, and you may use all of its features for free, but if you want to save your project as a sound file, then you must pay full price for their “Pro” version. Otherwise, you may only save your files to be used with this app and nothing else.